Cretaceous

The period 135-65 million years ago. Dinosaurs become increasingly specialized, and the first dinosaur management consultants arise. Then the dinosaurs suddenly die out. Hmmm....

The Rocky Mountains are formed. The Mesozoic era ends, and the age of mammals has begun.

Back: Jurassic

Cre*ta"ceous (krE*tA"shus), a. [L. cretaceus, fr. creta chalk. See Crayon.]

Having the qualities of chalk; abounding with chalk; chalky; as, cretaceous rocks and formations. See Chalk.

Cretaceous acid, an old name for carbonic acid. --
Cretaceous formation (Geol.), the series of strata of various kinds, including beds of chalk, green sand, etc., formed in the Cretaceous period; -- called also the chalk formation. See the Diagram under Geology. --
Cretaceous period (Geol.), the time in the latter part of the Mesozoic age during which the Cretaceous formation was deposited.

© Webster 1913

Cre*ta"ceous, a. Also Cre*tac"ic (&?;). (Geol.)

Of, pertaining to, or designating, the period of time following the Jurassic and preceding the Eocene.

© Webster 1913